Ethers



Patented May 21, 1940 UNITED STATES PATENT OFFICE (ALKYL- HALO-PHENOXY-ALKYL) (THIOCYANO-ALKYL) ETHERS Gerald H. Coleman, Midland,Mich., and Robert W. Sapp, Cambridge, Mass, assignors to The DowChemical Company, Midland, Mich., a corporation of Michigan No Drawing.Application May 1, 1939, Serial No. 271,172

9 Claims.

high-boiling liquids substantially insoluble inwater, soluble in mostpetroleum distillate fractions,

and somewhat soluble in organic solvents generally. They are useful asinsecticidal toxicants,

particularly when dissolved in non-corrosive orm ganic solvents.

These compounds may be prepared. by reacting the halo-alkoxy-alkylethers of alkyl-halo phenols with alkali metal thiocyanates in thepresence of alcohol. For example, an ether, such as thebetachloro-ethoxy-ethyl ether of chloro-meta-cresol,

may be dispersed in an alcoholic solution of potassium thiocyanate andthe mixture heated to its boiling temperature and under reflux for aperiod of time sufiicient to accomplish the reaction. The reactiontemperature isgenerally between 75. and 90 0., although somewhat loweror higher temperatures may be employed, the reaction being carried outunder autogenoris pressure where temperatures above the boilingtemperature of the reaction mixture prevail. While substantiallyequimolecular proportions of the ether and inorganic thiocyanate havebeen found to give the desired organic thiocyanates in good yield, anysuitable proportions of reactants may be employed. The alcohol ispresent in the reaction mixture preferably in amount suflicient toretain the reactants and final thiocyanate ether product in solution,Following the reaction, the major portion of the alcohol solvent may berecovered by distillation and the residue diluted with water, whereby awater-immiscible layer of the (alkyl-halo-phenoxy-alkyl) (t hi 0 c y a no alkyl) ether is separated. If desired, this product may be recoveredby extraction with a suitable a solvent, such as benzene, and theextract fractionally distilled. In an alternate procedure, thewater-immiscible layer may be separated, as by decantation, washed withwater, and used as an insecticidal toxicant without further treatment.

A further purification method consists of filtering the crude reactionmixture to remove insoluble salts and thereafter fractionally distillingto isolate the desired compound.

The (alkyl-halo-phenoxy-alkyl) (halo-alkyl) ethers employed as reactantsin the preparation of our new compounds can be obtained by reactingsuitable phenolates with the di-(halo-alkyl) ethers under conditions oftemperature and pressure that favor the replacement of a. single halogenatom by the alkyl-halo-phenoxy group.

A co-pending application Serial No. 225,414, file Augustl'l, 1938 by G.H. Coleman and C. L. Moyle discloses the preparation and properties of anumber of these compounds.

The following examples set forth certain em- 5' bodiments. of ourinvention, but are not to be construed as limiting the same:

Example 1 88 grams (0.27 mole) of beta-(4-tertiary-butyl- 1o2.6-dichloro-phenoxy) -beta' -chloro-diethyl ether (boiling at 179-l80C. at 4 millimeters pres! sure), 29 grams. (0.297 mole) of potassiumthiocyanate, and 300 milliliters of ethyl alcohol were heated at -81 O.for 48 hours and under re- 15 flux. Alcohol was then distilled out ofthe reaction mixture, the residue diluted with water and extracted withbenzene. The benzene extract was dried and fractionally distilled,whereby there was obtained 45 grams (0.13 mole) of beta-(4- ,0tertiary-butyl-2.6-dichloro-phenoxy) -b.eta -thiocyano-diethyl ether asa viscous liquid boiling at 227-229 C. at 4 millimeters pressure andhaving a specific gravity of 1.225 at 20/4 C. A 3 per cent solution ofthis compound in kerosene was tested according to the Feet-Grady method,substantially as described in Soap 8, No. 4, 1932, and found to give aknockdown of 100 per cent in 10 minutes against three-day old houseflies. The

observed kills after 24 and 48 hours were and so I per cent,respectively. This spray composition was substantially odorless and. hadlittle or no irritating effect upon the mucous membrane.

Example 2 grams (0.413 mole) of beta-(4-tertiary- 35butyl-2-chloro-phenoxy) beta chloro diethyl ether (boiling at 184-189 C.at '7 millimeters pressure) was mixed with 40 grams (0.413 mole) ofpotassum thiocyanate and milliliters of o absolute alcohol and themixture heated to a refluxing temperature for 48 hours. The reactionmixture was diluted with water and extracted with ethylene dlbromide.The extract was fractionally distilled, whereby there was obtained 548.9 grams of beta-(4-tertiary-butyl-2-chlorophenoxy)-beta-thiocyano-diethyl ether as a pale, yellow oil boiling at 245249 C.at 12 millimeters pressure and having a specific gravity of 1.166 at25/4 C. A 3 per cent solution of this compound 50 in kerosene, whentested as described in Example 1, knocked down 100 per cent of the testinsects in 10 minutes and killed 66 per cent and 80 per cent thereof in24 and 48 hours, respectively.

In a similar manner, related (alkyl-halo- 55 cyano-dipropyl ether;

phenoxy-alkyl) (thiocyano-alkyl) ethers may be prepared by substitutingother halo ethers for those shown in the examples. Representative ofsuch compounds are:beta-(2-methyl-4.6-dichloro-phenoxy)-beta-thiocyano-diethy1 ether; beta-(2-methyl- 4-bromo-phenoxy)-beta-thiocyano-diethyl ether;beta-(2-methyl-5-isopropyl- 4 bromo phenoxy) beta thiocyano diethylether; beta- (Z-isopropyl-5-methy1-4-chloro-phenoxy)beta'-thiocyano-diethyl ether; beta- (2.4.5- trimethyl 6 chloro-phenoxy)-beta'-thiocyanodiethyl ether;beta-(2.4.5-trimethyl-3.6-dichlorophenoxy)-beta-thiocyano-diethyl ether;beta- (Z-tertiary-butyl-3.4.6-trich1oro-phenoXy) -beta'-thiocyano-diethyl ether; beta-(3-methyl-2.4.5.6- tetrachloro phenoxy)beta-thiocyano-diethyl ether; beta- (2.5-diisopropyl-4-bromo-phenoxy)beta thiocyano diethyl ether; beta (tetramethyl chloro phenoxy)beta-thiocyano-diethyl ether; beta-(2.4-ditertiary-amyl-G-bromophenoxy)-beta'-thiocyano-diethyl ether; beta- (2 iodo 4-tertiary-hexyl-phenoxy)-beta-thiocyano-diethyl ether; beta-(2-normal-octyl-4- chloro 6bromo-phenoxy) -beta-thiocyano-diethyl ether;beta-(4-hexaclecyl-6-chloro-phenoxy) -beta-thiocyano-diethyl ether;beta- (2.4.6- tritertiary-butyl-3-chloro-phenoxy) beta thiogamma-(4-isopropyl-2- bromo phenoxy) gamma-thiocyano-dipropyl ether;(beta-3-methyl-fi-bromo-phenoxy-ethyl) (gamma thiocyano propyl) ether;delta-(3- methyl 4 chloro phenoxy) -delta-thiocyanodibutyl ether;(4-ethyl-6-chloro-phenoxy-hexyl) (thiocyano-hexyl) ether.

While the present invention relates broadly to all(alkyl-halo-phenoxy-alkyl) (thiocyano-alkyl) ethers, it is particularlyconcerned with those compounds having the following formula wherein eachR represents an alkylene radical, X represents halogen, n, a, and b areintegers, and the sum of a. and b is not greater than 5. V Thisapplication is a continuation-in-part of our co-pending applicationSerial No. 229,871, filed September 14, 1938.

We claim:-

1. A compound having the formula nH n u wherein each R represents analkylene radical, X

represents halogen, 1L, a, and b are integers, and

the sum of a and b is not greater than 5.

2. A compound having the formula wherein X represents halogen, n, a, andb are integers, and the sum of a and b is not greater than 5.

3. A compound having the formula wherein each R represents an alkyleneradical, X represents halogen, and n is an integer. 4. A compound havingthe formula wherein each R represents an alkylene radical, n, a, and bare integers, and the sum of a and b is not greater than 5.

5. A compound having the formula wherein n, a, and b are integers, andthe sum of a and b is not greater than 5.

6. A compound having the formula wherein Y represents a branched chainalkyl radical, X represents halogen, and a and b are integers, the sumof which is not greater than 5.

'7. A compound having the formula GERALD H. COLEMAN. ROBERT W. SAPP.

